1. Field of the Invention
The invention is generally related to the area of consumer electronics. In particular, the invention is related to method and apparatus for automatically coupling an appropriate voltage or power supply to an audio amplifier in a system in responding to a volume so as to increase the efficiency of the system.
2. The Background of Related Art
An electronic amplifier is a device for increasing the power of a signal. It achieves this amplification by taking power from a power supply and controlling the output to match the input signal but with gain. An idealized amplifier may be said to be “a piece of wire with gain”, as the output is an exact replica of the input, but larger.
Many electronic devices usually contain one or more amplifiers to energize audio signals before the audio signals are sent to speakers for sound reproduction. Ideally, the more amplifiers there are, the better the sound can be reproduced from the audio signals. Practically, there are many limitations in a device that limit the use of the amplifiers or power supplies. Examples of these limitations include physical dimensions, weight, costs, power consumption, and heat dissipation. Depending on application of an electronic device, appropriate amplifiers shall be designed and operate with appropriate power supply. Thus, there is always a need for efficient designs in an audio system that produces the best audio quality possible without going beyond physical design limitations.